The invention is based on an apparatus having a control motor for intervention into a force transmission device, between an operating element and a control device that determines the output of a driving engine, as defined hereinafter.
For various closed-loop control tasks in driving engines, intervention into a force transmission device between the operating element, such as a gas pedal, and the control device, such as a throttle valve in an Otto engine or a control lever of a Diesel engine or the like, is necessary. One reason for an adjustment may for instance be to avoid slip between wheels of a motor vehicle that are driven by the driving engine and a road surface.
A known apparatus includes a first driver element connected to the operating element, a second driver element, connected to the control device upon which control motor can act under certain circumstances. A coupling spring acts on one end on the first driver element and o the other on the second driver element, with the tendency to actuate a coupling stop of one driver element toward a coupling stop of the other driver element.
A restoring spring connected to the control device acts upon the control device in a direction of reduced output of the driving engine. In an unregulated operating state, action can be exerted upon the control device in the direction of greater output of the driving engine by the operating element, via the two driver elements. The operating element in this process operates counter to a restoring spring. The force of the restoring spring acts via the two driver elements and the coupling spring as far as the operating element. To prevent the two coupling stops from separating from one another in the unregulated operating state, the coupling spring must be embodied as markedly stronger than the restoring spring. The necessarily strong coupling spring leads to a relatively voluminous and heavy construction.
It is disadvantageous that when the control motor is triggered, the strong coupling spring tenses, causing considerable forces to be fed back to the operating element. An adjusting force to be brought to bear by the control element is relatively great.